/* 
 * Copyright 2010 Ziya Guven Koylu, Ozge Koylu
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at 
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
package com.koylu.caffein.model.clazz;

import com.koylu.caffein.exception.ClazzConfigException;
import com.koylu.caffein.model.caffein.CaffeinConfig;

public class ForeignKey extends Key {

	private String path;
	private Column refNode;
	private ColumnField realNode;
	
	//ForeignKey --> Column  
	public Column getRefNode(CaffeinConfig caffeinConfig) throws Exception{
		if (refNode == null) {
			refNode = ((Relation) getParent()).getForeignClazz(caffeinConfig).getColumn(getRefColumn(caffeinConfig));
			if( refNode == null ){
				throw new ClazzConfigException("column:"+getRefColumn()+" not found in the foreign clazz", this);
			}
		}
		return refNode;
	}

	//ForeignKey --> ColumnField 
	public ColumnField getRealNode(CaffeinConfig caffeinConfig) throws Exception{
		if (realNode == null) {
			Column column = getRefNode(caffeinConfig);
			while (!(column instanceof ColumnField)) {
				column = column.getRealNode(caffeinConfig);
			}
			realNode = (ColumnField) column;
		}
		return realNode;
	}

	public String getPath(CaffeinConfig caffeinConfig) throws Exception{
		if (path == null) {
			Node clazz = getParent();
			while(clazz.getParent() != null) {//!(clazz instanceof Clazz)
				path = ((Field) clazz).getName() + (path == null ? "" : "." + path);
				clazz = clazz.getParent();
			}
			path = path + "." + getRefNode(caffeinConfig).getPath(caffeinConfig);
		}
		return path;
	}
}